Abstract TP55: Prehospital Stroke Scale: Classifying The Inconclusive Result

Abstract

Introduction: The Cincinnati Pre-Hospital Stroke Scale (CPSS) is one of the most utilized, validated tools for stroke assessment by emergency medical services (EMS) providers. While the CPSS was developed to convey that a patient has a positive or negative finding, EMS providers designate some patients with “inconclusive” CPSS. To date, there is no data concerning the clinical presentation or stroke diagnosis of this cohort of patients. Methods: Retrospectively reviewed prehospital electronic medical records from 26 EMS agencies linked with hospital data of patients stroke alerted between April 1, 2020 to July 12, 2021 in our institution. The National Emergency Medical Services Information System Technical Assistance Center (NEMSIS TAC) 2020 Dataset was also evaluated. Data collected included CPSS, EMS chief complaint, EMS primary impression, and final discharge diagnosis. Results: At our institution 362 patients arrived by EMS and were stroke alerted at the hospital, of which 311 patients had a recorded prehospital CPSS. CPSS was recorded as inconclusive in 33.4% (104/311), positive in 52.1% (162/311), and negative in 14.5% (45/311) of patients. Neurological symptoms accounted for 76.9% (80/104) of EMS primary impression for those classified as inconclusive. Sixty percent (48/80) and 18.8% (15/80) of those were stroke-like symptoms and altered mental status, respectively. Stroke/TIA was the discharge diagnosis for 30.8% (32/104) of inconclusive, 63.6% (103/162) of positive, and 37.8% (17/45) of negative CPSSs. Nationally, 7.3% (142,422/1,955,591) of prehospital patients with recorded CPSS had an inconclusive finding. Among patients with primary impression of stroke-like symptoms with recorded prehospital CPSS, 17.3% (21,740/125,581) had an inconclusive label. Conclusion: Inconclusive CPSS designations in the prehospital setting are common. Although these patients present commonly with stroke-like symptoms, they have a low rate of stroke diagnosis. More studies with available prehospital linked hospital data are needed at a national level to understand the inconclusive prehospital CPSS designation and inform proper EMS education on in-practice use of stroke screening tools that reduce the number of inconclusive CPSS.